Copper indium gallium (di)selenide (CIGS) is a commonly used absorber layer in thin film solar cells. CIGS thin film solar cells have achieved excellent conversion efficiency (>20%) in laboratory environments. Most conventional CIGS deposition is done by one of two techniques: co-evaporation or selenization. Co-evaporation involves simultaneously evaporating copper, indium, gallium and selenium. The different melting points of the four elements makes controlling the formation of a stoichiometric compound on a large substrate very difficult. Additionally, film adhesion is very poor when using co-evaporation. Selenization involves a two-step process. First, a copper, gallium, and indium precursor is sputtered on to a substrate. Second, selenization occurs by reacting the precursor with toxic H2Se/H2S at 500° Celsius or above. Because this two-step reaction involves both gas (Se, or H2Se) diffusion and chemical reaction, the film composition profile is also difficult to control.